Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual page 207

■Tool radius compensation start and Z-axis cutting operation
At the start of cutting, normally radius compensation is applied beforehand at a location away from the work (normally the X-Y
plane), followed by cutting by the Z-axis. When the Z-axis operation is divided into two stages, a fast forward stage and cutting
after making contact with the work, take caution with the following when programming.
For the following G-code program (program 1), at the start of N1 compensation up to N6 block can be read, thus the
relationship between N1 and N6 is determined and compensation is correctly performed as illustrated below.
: Program path, : Tool center path
Program 1
N1 G91 G00 G41 X500. Y500. D01
N2 M1000
N3 M3
N4 G01 Z-150. F1
N6 Y100. F2
When the N4 block of the G-code program (program 1) above is divided into two, there are four blocks without a command
from N2 to N5 and on the X-Y plane, therefore at the start of N1 compensation, up to N6 block cannot be read. Consequently,
compensation is performed based on the information of N1 block only, and at the start of compensation a compensation
vector cannot be created, and overcutting occurs.
: Program path, : Tool center path
Program 2
N1 G91 G00 G41 X500. Y500. D01
N2 M1000
N3 M3
N4 Z-100.
N5 G01 Z-50. F1
N6 Y200. F2
Operation
N6
N4
Y
N1
X
N1
N4
N6
Z
Operation
N6
N4 to N5
Y
N1
X
N1
N4
N5
N6
Z
N6
N4
Y
N1
Z
X
N6
N4
N5
Y
N1
Z
X
6 AUXILIARY AND APPLIED FUNCTIONS
6.4 Tool Compensation Function
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